Applicator with a heating member for applying a cosmetic product on keratinous fibers

ABSTRACT

The invention relates to an applicator ( 1 ) comprising:
         a gripping member ( 5 ), a tip ( 10 ) attached to the gripping member ( 5 ), and an application member ( 15 ), the tip ( 10 ) comprising a heating member ( 25 ) for heating the application member ( 15 ), and   a source of electricity ( 20 ) for powering the heating member ( 25 ), a unit ( 30 ) for controlling the source of electricity ( 20 ), a first temperature sensor ( 35 ),
 
characterized in that the unit ( 30 ) is suitable for:
   producing, on the basis of the first parameter, a second parameter representative of the rate of the temperature rise of the heating member ( 25 ), and   comparing the second parameter to at least one threshold value stored in memory in the unit ( 30 ) and, on the basis of the result of the comparison, switching off the electrical power supply of the heating member ( 25 ).

The present invention relates to an applicator for applying a cosmeticproduct on keratinous fibers, the applicator comprising a grippingmember, a tip attached to the gripping member, and a member for applyingthe cosmetic product intended to be rigidly connected to the tip duringthe application of the cosmetic product, the tip comprising a heatingmember for heating the application member so as to enable theapplication of the cosmetic product on keratinous fibers, and a sourceof electricity for electrically powering the heating member and inducinga temperature rise of the heating member, a unit for controlling thesource of electricity, at least a first temperature sensor suitable forsupplying the unit with at least a first parameter representative of thetemperature of the heating member or of the tip.

The cosmetic product is for example a mascara, a care product, or acleansing product.

By “cosmetic product”, in the sense of this invention, we more generallymean a product as defined in EC Regulation n° 1222/2009 of the EuropeanParliament and the Council of Nov. 30, 2009, relating to cosmeticproducts.

The application member is for example a removable comb comprising thecosmetic product to be applied.

A user seeking to use the applicator activates the source of electricityto electrically power the heating member. This induces a temperaturerise therein. The control unit serves to regulate the temperature of theheating member so as to reach a target temperature. The cosmetic productcontained in the application member is heated by conduction, enablingthe application thereof on keratinous fibers.

However, if the user omits to place the application member on the tipand nonetheless activates heating, electricity consumption takes placeat a loss.

Similarly, if the application member is for example a pin intended to beextended into a reservoir containing the cosmetic product, and the useractivates heating, the source of electricity is used at a loss.

The use of the source of electricity at a loss reduces the service lifeor the autonomy in terms of power of the applicator.

One aim of the invention is thus that of providing an applicator havingan enhanced service life or autonomy in terms of power.

To this end, the invention relates to an applicator of the typedescribed above, wherein the unit is suitable for producing, on thebasis of the first parameter, a second parameter representative of therate of the temperature rise of the heating member, and comparing thesecond parameter to at least one threshold value stored in memory in theunit and, on the basis of the result of the comparison, switching offthe electrical power supply of the heating member.

According to particular embodiments of the invention, the applicatorcomprises one or several of the following features taken in isolation orin any technically possible combination:

-   -   the threshold value is an upper threshold, and the unit is        suitable for detecting whether the second parameter is greater        than or equal to the upper threshold, and, if so, switching off        the electrical power supply of the heating member.    -   the threshold value is a lower threshold, and the unit is        suitable for detecting whether the second parameter is less than        or equal to the lower threshold, and, if so, switching off the        electrical power supply of the heating member.    -   the second parameter is taken from a derivative of the first        parameter over time, a value of the first parameter adopted by        the first parameter after a given time during which the heating        member is powered by the source of electricity, a time taken by        the first parameter to reach a given value, or a time constant        of the temperature rise of the heating member, or combinations        thereof, particularly linear combinations thereof.    -   it comprises a second temperature sensor suitable for measuring        at least a third parameter, the third parameter being        representative of the ambient temperature when the application        member is not rigidly connected to the tip, the second parameter        being computed by the unit using the first parameter and the        third parameter.    -   the second temperature sensor is situated substantially at a        distal end of the tip relative to the gripping member.    -   it further comprises a thermal insulator situated longitudinally        between the second temperature sensor and the heating member.    -   the application member is removable, and preferably has a comb        general shape.    -   it comprises a reservoir suitable for receiving the cosmetic        product, the application member being movable between an idle        position, wherein the application member is situated in the        reservoir, and a use position, wherein the application member is        situated outside the reservoir, the application member        preferably having a general brush shape.

The invention also relates to a method for applying a cosmetic producton keratinous fibers, the method comprising at least the followingsteps:

-   -   providing an applicator comprising: a gripping member; a tip        attached to the gripping member; a member for applying the        cosmetic product intended to be rigidly connected to the tip        during the application of the cosmetic product, the tip        comprising a heating member; a source of electricity; a unit for        controlling the source of electricity; and at least a first        temperature sensor,    -   supplying electrical power to the heating member by means of the        source of electricity to induce a temperature rise of the        heating member,    -   heating the cosmetic product by means of the heating member so        as to enable the application of the cosmetic product on        keratinous fibers,    -   supplying the unit, by means of the first temperature sensor,        with at least a first parameter representative of the        temperature of the heating member,    -   producing by means of the unit, on the basis of the first        parameter, a second parameter representative of the rate of the        temperature rise of the heating member, and    -   comparing, by means of the unit, the second parameter to at        least one threshold value stored in memory in the unit, and, on        the basis of the result of the comparison, switching off the        electrical power supply of the heating member by the unit.

The invention will be easier to understand in view of the followingdescription, provided solely as an example and with reference to theappended drawings, wherein:

FIG. 1 is a perspective view showing the external appearance of anapplicator according to a first embodiment of the invention,

FIG. 2 is a cross-sectional view schematically representing theapplicator shown in FIG. 1

FIG. 3 is a graph illustrating the temperature rise of the heatingmember of the applicator represented in FIGS. 1 and 2,

FIG. 4 is a schematic, cross-sectional view of an applicator accordingto a second embodiment of the invention, and

FIG. 5 is a graph illustrating the temperature rise of the heatingmember of the applicator represented in FIG. 4,

With reference to FIGS. 1 and 2, an applicator 1 according to theinvention is described. The applicator 1 is intended to apply a cosmeticproduct (not shown) on keratinous fibers (not shown), for exampleeyelashes, of a recipient (not shown). In general, the recipient is theuser of the applicator 1.

The applicator 1 has for example an elongated shape along a longitudinaldirection L.

The applicator 1 comprises a base acting as a gripping member 5, a tip10 attached to the gripping member, and an application member 15suitable for applying the cosmetic product. The applicator 1 furthercomprises a source of electricity 20 (FIG. 2) for electrically poweringa heating member 25, a unit 30 for controlling the source ofelectricity, and at least a first temperature sensor 35 suitable forsupplying the unit 30 with at least a first parameter T representativeof the temperature of the heating member.

Optionally, the applicator 1 also comprises a second temperature sensor40 and a thermal insulator 45, advantageously situated at a distal endof the tip 10.

The cosmetic product is for example a mascara.

The gripping member 5 is suitable for handling by the user. The grippingmember 5 comprises for example two half-shells assembled together andmade of plastic.

The gripping member 5 advantageously comprises an on-off button 47. Inthe example shown, the gripping member 5 also comprises an operatinglight 49, for example a light-emitting diode.

The tip 10 has for example a general tubular shape. The tip 10advantageously comprises a metal tube 51. The tip 10 extends for examplealong the longitudinal direction L. The tip 10 comprises a proximal end53 relative to the gripping member 5.

The proximal end 53 is attached to the gripping member 5.

The metal tube 51 comprises for example an open distal end 55.

The application member 15 is advantageously removable. The applicationmember 15 is movable between a position wherein it is removed from thetip 10 (FIG. 1), and an application position (FIG. 2) wherein theapplication member is connected to the tip 10. For example, theapplication 15 is attached to the tip 10 in the application position.

According to further embodiments not shown, the application member 15 isconnected to the tip 10 by any means known to those skilled in the art.For example, the application member 15 is rotatably mounted on the tip10, advantageously about the longitudinal direction L.

The application member 15 has for example a general comb shape. Theapplication member 15 comprises teeth 57 suitable for applying thecosmetic product on keratinous fibers.

The application member 15 defines an inner recess suitable for receivingthe tip 10 longitudinally in the application position.

The teeth 57 are advantageously oriented substantially radially from thelongitudinal direction L. For example, the teeth 57 extend in ahalf-space defined by a median plane P of the application member 15.

The source of electricity 20 is for example a battery, advantageouslyrechargeable. The source of electricity 20 is advantageously situatedinside the gripping member 5.

The source of electricity 20 is suitable for delivering a ratedelectrical power between 0.5 and 2 W.

The first temperature sensor 35 is for example a thermocouple.

According to alternative embodiments not shown, the first temperaturesensor 35 is a Hall effect sensor or a switch.

The first temperature sensor 35 is for example situated inside the tip10. The first temperature sensor 35 is advantageously situated in thevicinity of the heating member 25, i.e. for example at a distance fromthe heating member 25 less than 10 mm.

According to one advantageous embodiment, the first temperature sensor35 is situated on the heating member 25.

The first parameter T representative of the temperature of the heatingmember 25 is advantageously the temperature of the heating member.

The heating member 25 is for example a resistive printed circuit board(PCB). The heating member 25 is electrically connected to the source ofelectricity 20.

The unit 30 is suitable for producing, on the basis of the firstparameter T, a second parameter T1 or T2 (FIG. 3) representative of therate of the temperature rise of the heating member 25. The heatingmember 25 extends longitudinally inside the tip 10. Advantageously, theheating member 25 has longitudinally an extension E substantially equalto that of the application member 15.

The unit 30 is also suitable for comparing the second parameter T1 or T2to at least one threshold value Tmax stored in memory in the unit 30and, on the basis of the result of the comparison, switching off theelectrical power supply of the heating member 25 by the source ofelectricity 20.

In the example shown in FIGS. 1 to 3, the threshold value Tmax is anupper threshold. The unit 30 is suitable for detecting whether thesecond parameter T1 or T2 is greater than or equal to the upperthreshold, and, if so, switching off the electrical power supply of theheating member 25 by the source of electricity 20. Tmax is for exampleequal to approximately 55° C.

Again in the example represented in FIG. 3, the second parameter is forexample defined as being a value of the first parameter T adopted by thefirst parameter after a given time during which the heating member 25 iselectrically powered by the source of electricity 20. For example, thegiven time is 10 seconds.

According to further embodiments not shown, the second parameter istaken from: a derivative of the first parameter T over the time t, atime taken by the first parameter T to reach a given value, or, moregenerally, a time constant of the temperature rise of the heating member25 at the start of heating.

According to one particular embodiment, the second parameter is acombination of the possibilities cited above, particularly a linearcombination.

The second temperature sensor 40 is situated substantially at the distalend 55 of the metal tube 51 relative to the gripping member 5.

The second temperature sensor 40 is suitable for supplying the ambienttemperature when the application member 15 is not present. When theapplication member 15 is in place, the temperature is slightly higher byapproximately 4 degrees, due to more limited heat exchanges with theambient. This is a second, less preferential, way of detecting thepresence or absence of the application member 15.

The thermal insulator 45 is for example made of elastomer. The insulator45 is situated longitudinally between the second temperature sensor 40and the heating member 25.

The operation of the applicator 1 shall now be described.

To use the applicator 1, a user moves the application member 15 from theremoved position represented in FIG. 1, to the application positionrepresented in FIG. 2. The application member 15 is then in contact withthe tip 10, in the vicinity of the heating member 25.

Then, the user presses the switch 47 to activate the electrical powersupply of the heating member 25 from the source of electricity 20. Thisinduces a temperature rise of the heating member 25, illustrated by acurve C1 in the graph in FIG. 3.

This graph shows the progression of the first parameter T, i.e. in thiscase the temperature of the heating member 25, as a function of the timet.

The cosmetic product contained in the application member 15 is heated bythe heating member 25, enabling the application of the cosmetic producton keratinous fibers.

The first temperature sensor 35 measures the first parameter T andsupplies same to the unit 30.

The unit 30, on the basis of the first parameter T, produces the secondparameter T1 representative of the rate of the temperature rise of theheating member 25. The second parameter T1 is at the value of the firstparameter T after 10 seconds for example. T1 is for example equal toapproximately 50° C.

Then, the unit 30 compares the second parameter T1 to the thresholdvalue Tmax, which is in this case an upper threshold. If the secondparameter T1 is less than or equal to the threshold value Tmax, the unit30 does not switch off the electrical power supply of the heating member25 by the source of electricity 20. This is the case here, as T1 is 5°C. less than Tmax.

The unit 30 further advantageously carries out a regulation function,known per se, enabling the first parameter T to reach a targettemperature Tc. Tc is for example equal to approximately 80° C.

In this regulation function, the unit 30 is optionally required toswitch off or modify the electrical power supply of the heating member25, but the unit does not do so on the basis of a parameterrepresentative of the temperature rise of the heating member 25following the start-up of the applicator 1.

However, if the user omits to place the application member 15 on the tip10 before use, the temperature rise of the member 25 recorded by thetemperature sensor 35 is represented by a curve C2. The curve C2 shows amore rapid temperature rise than that of the curve C1 due to the lack ofthermal dissipation of the heat generated by the heating member 25 inthe application member 15.

In this case, the second parameter produced by the unit 30 adopts avalue T2 greater than the threshold value Tmax. The unit 30 thenswitches off the electrical power supply of the heating member 25. Onceagain, this switching off is not suitable for regulating the firstparameter T, but results from a comparison of the second parameter,representative of the rate of the temperature rise of the heating member25, with a threshold value.

By means of the features described above, the applicator 1 is capable ofdetecting the absence of the application member 15 in contact with thetip 10, and of switching off the electrical power supply of the heatingmember 25. This makes it possible to prevent unnecessary heating by theheating member 25, and thus enhance the service life of the autonomy interms of power of the application 1.

In addition, this also makes it possible to prevent the tip 10 fromreaching a relatively high temperature potentially causing burning ofthe user if the latter were to apply the tip 10 directly onto keratinousfibers.

A further way of detecting the presence or absence of the applicationmember 15 is that of measuring the difference in temperature between theambient temperature and a reference temperature at the secondtemperature sensor 40. The reference temperature is the expectedtemperature in the absence of the application member 15. The temperaturevariation observed in the presence of the application member 15 isslight, in the region of approximately 4 degrees. For this reason, thismethod is not preferential.

With reference to FIGS. 4 and 5, an applicator 100 according to a secondembodiment of the invention is described. The applicator 100 is similarto the applicator 1 represented in FIGS. 1 and 2. Similar elements bearthe same reference numbers and shall not be described a second time.Only the differences shall be described hereinafter.

The applicator 100 comprises a reservoir 101 suitable for receiving thecosmetic product, for example a mascara.

The application member 15 is movable between an idle position (FIG. 4)wherein the application member is situated in the reservoir 101, and ause position (not shown) wherein the application member is situatedoutside the reservoir and which is suitable for applying the cosmeticproduct onto keratinous fibers.

The application member 15 has for example a general brush shape. Theapplication member 15 comprises bristles 157 oriented substantiallyradially from the longitudinal direction L. The bristles 157 are forexample distributed at an angle about the longitudinal direction L in asubstantially regular manner.

The applicator 100 comprises a heating member 125 having a filamentshape wound around the application member 15, for example in a spiral.

In the idle position, the gripping member 5 is for example screwed ontothe reservoir 101.

The tip 10 has for example a rod shape.

In the example, the application member 15 is not removable. Theapplication member 15 is advantageously situated at the end of the tip10.

The operation of the applicator 100 shall now be described.

With reference to FIG. 5, the temperature sensor 35 of the applicator100 supplies the first parameter T representative of the temperature ofthe heating member 125.

During normal use, i.e. when the application member 15 is in the useposition, the temperature rise takes place according to a curve C3 seenin FIG. 5.

The unit 30 produces a second parameter T1, which is in the example thevalue adopted by the first parameter T after 10 seconds. The unit 30compares the second parameter T1 to a threshold value Tmin, which is inthis case a lower threshold.

T1 is for example equal to 50° C.

Tmin is for example equal to 40° C.

If the second parameter T1 is greater than or equal to the thresholdvalue Tmin, which is the case herein, the unit 30 does not switch offthe electrical power supply of the heating member 125. The temperaturerise continues and the unit 30 carries out the function thereof forregulating the first parameter T at the target value Tc.

However, if the user activates heating while the application member 15is in the idle position thereof, i.e. in the reservoir 101, thetemperature rise, represented by a curve C4 in the FIG. 5, is muchslower, or even non-existent.

The unit 30 produces a second parameter T2 which is then less than thevalue Tmin. The control unit 30 switches off the electrical power supplyof the heating member 125 by the source of electricity 20.

T2 is close to the ambient temperature and for example is equal toapproximately 25° C. By means of the features described above, theapplicator 100 is suitable for preventing unnecessary heating of theheating member 125.

1. Applicator for applying a cosmetic product on keratinous fibers; theapplicator comprising: a gripping member, a tip attached to the grippingmember, and a member for applying the cosmetic product intended to berigidly connected to the tip during the application of the cosmeticproduct, the tip comprising a heating member for heating the applicationmember so as to enable the application of the cosmetic product onkeratinous fibers, and a source of electricity for electrically poweringthe heating member and inducing a temperature rise (C1, C2, C3, C4) ofthe heating member, a unit for controlling the source of electricity, atleast a first temperature sensor suitable for supplying the unit with atleast a first parameter (T) representative of the temperature of theheating member or of the tip, wherein the unit is suitable for:producing, on the basis of the first parameter (T), a second parameter(T1, T2) representative of the rate of the temperature rise (C1, C2, C3,C4) of the heating member, and comparing the second parameter (T1, T2)to at least one threshold value (Tmax, Tmin) stored in memory in theunit and, on the basis of the result of the comparison, switching offthe electrical power supply of the heating member.
 2. Applicatoraccording to claim 1, wherein: the threshold value (Tmax) is an upperthreshold, and the unit is suitable for detecting whether the secondparameter (T1, T2) is greater than or equal to the upper threshold, and,if so, switching off the electrical power supply of the heating member.3. Applicator according to claim 1, wherein: the threshold value (Tmin)is a lower threshold, and the unit is suitable for detecting whether thesecond parameter (T1, T2) is less than or equal to the lower threshold,and, if so, switching off the electrical power supply of the heatingmember.
 4. Applicator according to claim 1, wherein the second parameter(T1, T2) is taken from: a derivative of the first parameter (T) overtime (t), a value of the first parameter (T) adopted by the firstparameter (T) after a given time during which the heating member ispowered by the source of electricity, a time taken by the firstparameter (T) to reach a given value, or a time constant of thetemperature rise (C1, C2, C3, C4) of the heating member, or combinationsthereof, particularly linear combinations thereof.
 5. Applicatoraccording to claim 1, which comprises a second temperature sensorsuitable for measuring at least a third parameter, the third parameterbeing representative of the ambient temperature when the applicationmember is not rigidly connected to the tip, the second parameter (T1,T2) being computed by the unit using the first parameter (T) and thethird parameter.
 6. Applicator according to claim 5, wherein the secondtemperature sensor is situated substantially at a distal end of the tiprelative to the gripping member.
 7. Applicator according to claim 5which further comprises a thermal insulator situated longitudinallybetween the second temperature sensor and the heating member. 8.Applicator according to claim 1, wherein the application member isremovable.
 9. Applicator according to claim 1, which comprises areservoir suitable for receiving the cosmetic product, the applicationmember being movable between an idle position, wherein the applicationmember is situated in the reservoir, and a use position, wherein theapplication member is situated outside the reservoir, the applicationmember preferably having a general brush shape.
 10. Method for applyinga cosmetic product on keratinous fibers, the method comprising at leastthe following steps: providing an applicator comprising: a grippingmember; a tip attached to the gripping member; a member for applying thecosmetic product intended to be rigidly connected to the tip during theapplication of the cosmetic product, the tip comprising a heatingmember; a source of electricity; a unit for controlling the source ofelectricity; and at least a first temperature sensor, supplyingelectrical power to the heating member by means of the source ofelectricity to induce a temperature rise of the heating member, heatingthe cosmetic product by the heating member so as to enable theapplication of the cosmetic product on keratinous fibers, supplying theunit, by means of the first temperature sensor, with at least a firstparameter (T) representative of the temperature of the heating member,producing by the unit, on the basis of the first parameter (T), a secondparameter (T1, T2) representative of the rate of the temperature rise(C1, C2, C3, C4) of the heating member, and comparing, by the unit, thesecond parameter (T1, T2) to at least one threshold value (Tmax,Tmin)-stored in memory in the unit, and, on the basis of the result ofthe comparison, switching off the electrical power supply of the heatingmember by the unit.
 11. Applicator according to claim 2, wherein: thethreshold value (Tmin) is a lower threshold, and the unit is suitablefor detecting whether the second parameter (T1, T2) is less than orequal to the lower threshold, and, if so, switching off the electricalpower supply of the heating member.
 12. Applicator according to claim 2,wherein the second parameter (T1, T2) is taken from: a derivative of thefirst parameter (T) over time (t), a value of the first parameter (T)adopted by the first parameter (T) after a given time during which theheating member is powered by the source of electricity, a time taken bythe first parameter (T) to reach a given value, or a time constant ofthe temperature rise (C1, C2, C3, C4) of the heating member, orcombinations thereof, particularly linear combinations thereof. 13.Applicator according to claim 3, wherein the second parameter (T1, T2)is taken from: a derivative of the first parameter (T) over time (t), avalue of the first parameter (T) adopted by the first parameter (T)after a given time during which the heating member is powered by thesource of electricity, a time taken by the first parameter (T) to reacha given value, or a time constant of the temperature rise (C1, C2, C3,C4) of the heating member, or combinations thereof, particularly linearcombinations thereof.
 14. Applicator according to claim 2, whichcomprises a second temperature sensor suitable for measuring at least athird parameter, the third parameter being representative of the ambienttemperature when the application member is not rigidly connected to thetip, the second parameter (T1, T2) being computed by the unit using thefirst parameter (T) and the third parameter.
 15. Applicator according toclaim 3, which comprises a second temperature sensor suitable formeasuring at least a third parameter, the third parameter beingrepresentative of the ambient temperature when the application member isnot rigidly connected to the tip, the second parameter (T1, T2) beingcomputed by the unit using the first parameter (T) and the thirdparameter.
 16. Applicator according to claim 4, which comprises a secondtemperature sensor suitable for measuring at least a third parameter,the third parameter being representative of the ambient temperature whenthe application member is not rigidly connected to the tip, the secondparameter (T1, T2) being computed by the unit using the first parameter(T) and the third parameter.
 17. Applicator according to claim 6 whichfurther comprises a thermal insulator situated longitudinally betweenthe second temperature sensor and the heating member.
 18. Applicatoraccording to claim 2, wherein the application member is removable. 19.Applicator according to claim 3, wherein the application member isremovable.
 20. Applicator according to claim 4, wherein the applicationmember is removable.